BARCELONA, SPAIN—Plans to build a particle accelerator and neutron source in Spain’s Basque Country have come to a sudden halt. The governing board of the European Spallation Source (ESS)-Bilbao has removed the project’s scientific director, Javier Bermejo, a neutron scattering researcher at the Institute for the Structure of Matter in Madrid, and did not renew the contract of ESS-Bilbao’s executive director, retiring physicist Joan Bordas. In a statement, the board said the facility needs “an analysis and new impetus.” The moves appear to mark another turning point in a long-standing debate over whether ESS-Bilbao should be a freestanding facility primarily serving Spain, or mostly an R&D test bed serving a Europe-wide spallation source set to be built in Sweden.
ESS-Bilbao was formally launched in 2009, after Spain lost a bid to host the European Spallation Source, a $2.4 billion, high-power neutron facility that is anticipated to be fully operational in Lund, Sweden, by 2025. Soon after European research ministers selected Sweden to host the ESS, the Spanish and Swedish science ministers signed a memorandum of understanding  pledging that “Spain and Sweden would work together, and that there would be a significant presence in Bilbao,” says Colin Carlile, who led the Swedish bid and was director-general of ESS until last February. The Spanish Ministry of Science and Innovation committed $240 million to developing a facility in Bilbao that would provide components and serve as a technology test bed for the Lund accelerator, in exchange for a 10% share in the ownership of ESS.
Bermejo, who was appointed ESS-Bilbao’s scientific director in late 2009, says that he has long seen the deal, “which gave all the control of the Spanish money to Lund,” as a missed opportunity. In the past few years, his team at ESS-Bilbao has drawn up plans for a more ambitious facility that he argues would yield better returns to the Basque region. “Spain has been contributing substantially to large-scale installations for about 30 years, without having any real laboratory [developed] to provide anything more complex than … bits and pieces of equipment,” Bermejo says. “That’s the situation we wanted to reverse.” In addition to developing accelerator components for Lund, ESS-Bilbao set out to build its own light-ion linear accelerator and neutron source for local accelerator physicists and beam users.
These grander aspirations ruffled feathers in Sweden. According to Carlile, scientists and engineers developing ESS in Lund have had an increasingly difficult time tapping into Spain’s industrial capability and beam user community. With ESS-Bilbao not living up to its 2009 commitment to channel their efforts toward Lund, the Spanish scientists and industrialists “chose to carry out research projects and to supply equipment at other international facilities,” Carlile explains.
Adding a layer of complexity, the same dilemma—whether a country should invest in access to a large international facility or build its own center to satisfy local needs—was also at play between Spain’s central government and the Basque government. In 2009, the two parties agreed to equally foot the $240 million bill for building up ESS-Bilbao. Bermejo says that would have covered construction costs at the University of the Basque Country and the facility’s operations through 2022. But what direction the Bilbao facility will take is now up in the air. At a press conference  on 30 August, the Basque president, Iñigo Urkullu, reiterated his support for a neutron source in Bilbao. Meanwhile, Spain’s competitiveness ministry, which now oversees science and innovation, has opened talks with Sweden on redirecting ESS-Bilbao to the original agreement.
Some Spanish neutron physicists would like to see a spallation source in the Basque Country. “This initiative was a breakthrough, not only for the Spanish neutron community, but also for a more general scientific community in Spain,” writes Jesús Blanco, a condensed-matter physicist at the University of Oviedo, in an e-mail to ScienceInsider. In a July 2012 report, ESS-Bilbao’s scientific advisory board concluded that ESS-Bilbao would have a niche as a standalone facility, and called for a revised memorandum of understanding.
Others disagree. Javier Campo, a physicist at the Materials Science Institute of Aragon in Zaragoza and chair of the Spanish Society of Neutron Techniques, says that the Spanish neutron community has its current needs largely met by the neutron source at the Institut Laue-Langevin in Grenoble, and wants to participate in building the next big machine. He believes that ESS-Bilbao’s budget and its scientific know-how are insufficient to compete with existing sources in Europe, especially with ESS Lund once it’s built. Because ESS-Bilbao’s funding was meant to be Spain’s contribution to ESS Lund, and because no intergovernmental funding agreement has been signed for the European facility, ESS-Bilbao’s divergent plans were threatening to “torpedo the European panorama,” Campo says.
Serving Lund’s needs would allow ESS-Bilbao to gain experience and eventually carve out its own niche in Europe, Campo adds. “That would be the ideal scenario.”